Unitized animal food system product

ABSTRACT

A simultaneously compacted, shaped, molded and unitized, self-contained, unit-integral, chew-resistant animal food system product containing animal food and structure-supporting fibers, preferably in a fibrous form, in an amount sufficient to make said product chew-resistant, self-contained and unit-integral and to enable it to be and remain in its compacted, shaped and molded form. The product contains sufficient structure-supporting fibers to yield a chew-resistant product. The structure-supporting fibers are animal safely digestible structure-supporting fibers, such as collagen, animal safely indigestible structure-supporting fibers, such as cellulosic materials, or a mixture of animal safely digestible structure-supporting fibers and animal safely indigestible structure-supporting fibers, such as a mixture of collagen and cellulosic materials. Illustrative food components are those animal foods currently used and known and are preferably in a dry, shelf-stable form such as dried meats, dried fish, fish meal, fish flour, cereals, fruits, etc., with or without food additives or supplements such as vitamins, minerals, medicinals, etc., for example chemicals, enzymes, etc., capable of removing plaque or tartar from the animal&#39;s teeth, etc. Sufficient structure-supporting fibers are mixed with the basic food components, the collagen thereof being preferably derived from animal skins or hides preferably in a fibrous form, and the structure-supporting fibers are capable of binding the food into the unitized chew-resistant product. Collagen, preferably derived from animal skins, is the preferred fiber. Also within the scope of this invention is a simultaneously compacted, shaped, molded and unitized, self-contained, unit-integral, chew-resistant multilayer animal food system product containing at least one chew-resistant layer and at least one lesser or non-chew-resistant layer, wherein the chew-resistance of said layers is primarily controlled or varied by the relative presence or absence of structure-supporting fibers incorporated into the particular layer of food components, as aforesaid, prior to contacting, said structure-supporting fibers being as aforesaid.

This Application is a continuation-in-part Application of myApplications, Ser. Nos. 117,081, filed on Feb. 19, 1971, now abandoned221,035, filed on Jan. 26, 1972 now abandoned and 242,428, filed on Apr.10, 1972 now abandoned.

This Application is also copending with Application Ser. No. 343,835,filed on Mar. 25, 1973, now U.S. Pat. No. 4,145,447 entitled"HighlyCompacted Animal Food System," Bernard W. Weinrich and I being and setforth as the joint inventors thereof and joint Applicants therefor.

My invention relates to my pet feeding unitized animal food systemproducts.

My pet feeding unitized animal food system products are simultaneouslycompacted, shaped, molded, and unitized, self-contained, unit-integral,chew-resistant animal food system product and contain animal food andstructure-supporting fibers. Said structure-supporting fibers are animalsafely digestible structure-supporting fibers or animal safelyindigestible structure-supporting fibers or a mixture of animal safelydigestible structure-supporting fibers and animal safely indigestiblestructure supporting fibers. Said structure-supporting fibers arepresent in my animal food system products of my invention in an amountsufficient to make each of my products chew-resistant, self-containedand unit-integral and to enable each of them to be and remain in itscompacted, shaped and molded form. Also within the scope of thisinvention is included my simultaneously compacted, shaped, molded andunitized, self-contained, unit-integral, chew resistant multilayeranimal food system product with at least one chew-resistant layer withanimal food as a part thereof at least one lesser chew-resistant layerlikewise with animal food being at least a part thereof, the latterlayer being less chew-resistant than said former layer, with thechew-resistance of each of said layers being primarily controlled by therelative presence or absence of structure-supporting fibers, asaforesaid, that is, animal safely digestible structure-supporting fibersor animal safely indigestible structure-supporting fibers or a mixtureof animal safely digestible structure-supporting fibers and animalsafely indigestible structure-suppporting fibers. Saidstructure-supporting fibers in my multilayer embodiment are present insaid latter layer and in said former layer or in said latter layer or insaid former layer in amounts or in an amount, as the case may be,sufficient to make said multilayer product chew-resistant,self-contained and unit-integral and to enable it to be and remain inits compacted, shaped and molded form.

The chew-resistance of each of my products, other than my multilayerproducts, as aforesaid, and as hereinafter described, is primarilycontrolled by the amount of structure-supporting fibers, as aforesaid,incorporated therein. With respect to my multilayer embodiments, thechew-resistance is, in addition, primarily controlled and/or varied bythe amount or absence of structure-supporting fibers, as aforesaid,incorporated into the particular layer of food components prior tocompacting.

As described in my copending Applications, Ser. Nos. 117,081 and221,035, and as herein disclosed and claimed, my single layer petfeeding system products are self-contained units in various sizes andshapes and are in essence characterized by a compacted, self-containedunit which contains the pet's meal. In practice the food components,generally in dry or low moisture content, are mixed and the mixturemolded into the desired size and shape. The size and shape will dependupon many factors, such as the size of the dog, the amount of foodrequired for the feeding, etc. For example, the size could be thatrequired for a single meal or increments thereof. The shape will dependupon the desired appearance, for example, the shape of a bone, a ball, aring, an animal, a human, a stick, or any other imaginative, abstract,whimsical, amorphous or actual shape.

As described in my copending Application Ser. No. 242,428, which is acontinuation-in-part of my said copending Applications, Ser. Nos.117,081 and 221,035, my multilayer embodiment is such that there areemployed at least one layer of a high chew-resistance and at least onelayer of lesser or non-chew-resistance. The chew-resistance or hardnessthereof can be controlled by a variety of techniques, for example, theamount and type of structure-supporting fibers, as aforesaid, thelength, shape, width, etc., of the fibers, as aforesaid, the presence,absence or relative amount of the binder employed, the pressure employedin compacting the product, etc. For example, by incorporatingstructure-supporting fibers in the base layer of dry dog food and thenpreparing a second layer of dry dog food without structure-supportingfibers, as aforesaid, there will be obtained, when compacted, one of mymultilayer products, as aforesaid, with an inner hard and chew-resistantlayer and an exterior layer relatively soft and crumbly as compared tosaid inner layer. Alternatively, by preparing an inner core withoutstructure-supporting fibers, as aforesaid, and then superimposing asecond layer with structure-supporting fibers, as aforesaid, thereon soas to yield a soft core layer and a hard exterior layer when compacted,the exterior layer will be hard and the inner, or interior, layer soft.By starting with a soft core layer and alternating the type of layers, Ican compose different alternate layer ad iinfinitum, such assoft/hard/soft/hard/etc. Alternately by starting with a hard core andthen superimposing a soft layer thereon, and alternating other layers, Ican obtain a product such as hard/soft/hard/soft/etc. In addition, thelayers may have varying degrees of hardness. Thus, one layer may behard, the second layer less hard, etc., or alternately soft, then hard,soft, hard, etc. In order to vary the chewing demand of the dog, theouter layer may be hard and the inner layer soft. By varying thethickness of each layer or number of alternate layers, a dog used to asoft diet could be gradually "weaned away" from such soft foods, whichdo not sufficiently exercise his teeth and jaws and remove plaque andtartar, to a chew-resistant product which is sufficiently hard toexercise his teeth and jaws and to remove plaque and tartar. Hard outercontainers of chew-resistant pet food can be prepared and filled withsofter pet food. The outer container can be in a wide variety of shapes,such as cones, cylinders, balls, squares, etc. In addition, by dipping acore repeatedly in rawhide or collagen fiber-containing pet food,chew-resistant layers or laminations of pet food can be built up toyield an extra hard chew-resistant product. Similarly, the hard and softlayer can be alternated or varied according to any desired pattern.Layers may be superimposed on one another so as to form a sandwich suchas one that has an inner soft layer and exterior hard layers; or viceversa. Soft and hard sections can also be prepared with interlockingmale and female indentions so that they can be joined together in thenature of jigsaw links into the desired configuration. By so joining,the desired shape in two or three dimensions can be created. Likewise,with respect to my multilayer embodiment, the shape will depend upon thedesired appearance, for example, the shape of a bone, a ball, a ring, ananimal, a human, a stick, or any other imaginative, abstract, whimsical,amorphous or actual shape.

In the drawing:

FIG. 1 illustrates one embodiment in the shape of a bone having a softexterior layer and a hard core layer.

FIG. 2 illustrates another embodiment in the shape of a bone having ahard exterior layer and a soft core layer.

FIG. 3 illustrates stock material with alternating layers.

With respect to all embodiments, shapes are illustrated in the followingU.S. Pat. Nos.: 3,104,648, Design Patents 202,330, 202,331, 202,332,207,167, etc.

With respect to all embodiments of this invention, I have discovered bypet feeding system products hereof characterized by self-contained unitsin various sizes and shapes and further characterized by my compactedself-contained units, as aforesaid and also as hereinafter furtherdescribed, which contains the pet's meal. In practice, the foodcomponents, generally in dry or low moisture content, are mixed with thestructure-supporting fibers, as aforesaid and also as hereinafterfurther described, and the mixture molded into the desired size andshape. In all embodiments, the respective sizes and shapes will dependupon many factors, such as the size of the pet, the amount of foodrequired for the feeding of the pet, etc. For example, the size could bethat required for a single meal or increments thereof.

Many pet foods are available on the market, including canned foods,dehydrated foods, etc. However, the moisture content of these knownfoods is in the extreme ranges, i.e. the food is either very dryrequiring the addition of water or has a high moisture content. Sincesaid known types of such foods have little, if any, unit integrity, thatis, they are not unit-integral, such known foods require containers andare not self-contained. My newly discovered unitized animal food systemproducts on the other hand are both unit-integral and self-contained anddo not require containers.

In addition, such known foods are so soft that the animal can "wolf"them down without much chewing, if any, so that the animal's jaws andteeth get little exercise. I have provided, for the first time, myunitized animal food system products which are chew-resistant and alsounit-integral and also self-contained as well as compacted, shaped andmolded. My products contain more than mere animal food; they contain, inaddition to the animal food, structure-supporting fibers, as aforesaidand as further hereinafter described, present in amounts sufficient tomake my products chew-resistant, self-contained (no packaging needed)and unit-integral and to enable them to be and remain in theircompacted, shaped and molded forms. Each of my products is a single mealor a predetermined incremental portion of a single meal. All heretoforeknown and used animal foods have been such that the animal has been ableto "wolf" them down without much chewing, if any, or that the animal hascaused them to crumble easily without any chewing action of anyconsequence. In preparing the products of my invention herein, it ishighly desirable that the molded units maintain their respective unitintegrity so that the animal will be able to satisfactorily exercise itsteeth, gums and jaws, and the molded units of my invention are such thatthey maintain their respective unit integrity so that the animal doesexercise satisfactorily its teeth, gums and jaws. Where the heretoforeknown and used animal foods are compacted without structure-supportingfibers, as aforesaid and as further hereinafter described, those foodsare crumbly, i.e. they disintegrate with little chewing action. Myproducts of this invention, on the other hand, do have unit-integrityand do have product "chew-life".

With respect to the animal food components in my products, it is, ingeneral, desirable that said food components have a satisfactoryshelf-life so that preservation is no problem. Such food componentsinclude many of the foods currently available such as air dried,freeze-dried, irradiated, etc. foods, such as meat, fish, fish meal,cereals, vegetables, fruits, wheat germ, protein flour derived fromfish, fish meal, etc. Many of these are currently available commerciallyunder a wide variety of names. In addition to such known foods, anydesired supplemental additives such as desired vitamins, food additives,medicines or other supplements, minerals, etc., can be added.

There have been cited various examples of heretofore known foods,including animal foods, by the Patent Office during the prosecution ofmy aforesaid Applications, and such were as follows: U.S. Pat. Nos.3,115,409, 2,802,737, 2,879,163, 3,323,922, 3,574,633 and 3,694,434together with a West and Todd publication on page 1326 of the Textbookof Biochemistry, published by MacMillan in 1967, relating only to"Fibers of Connective Tissue," said publication not mentioning food ofany kind and type and degree. Those examples do not even suggest, letalone disclose, in any manner, shape or form, each taken alone or eachin any combination desired, my products herein disclosed and alsoclaimed.

I have also discovered that the unit-integrity or "chew life" of theproducts of this invention of mine is enhanced by the incorporation ofstructure-supporting fibers, as aforesaid, in the molded embodimentsherein.

Any suitable structure-supporting fibers, as aforesaid and furtherhereinafter described, can be employed in this invention provided thatthey perform the function of binding the food into a unitizedchew-resistant product and are not harmful to the pet. Such fibersinclude those which may or may not be digested by the animal, providedthe pet's digestive system is capable of handling such fibers. Forexample, such fibers include animal safely digestiblestructure-supporting fibers, such as collagen, animal safelyindigestible structure-supporting fibers, such as cellulosic fibers, ormixtures of such animal safely digestible structure-supporting fibersand such animal safely indigestible structure-supporting fibers, thatis, mixtures of collagen and cellulosic fibers.

Now, a suitable source of animal safely digestible structure-supportingfibers include fibers derived from animal tissue--for example from theskin, muscles, intestines, etc. of animals, for example, from tendons,animal hides such as cowhide, rawhide, etc. One convenient method ofpreparing such animal safely digestible structure-supporting fibers isto cut, chip, grind, shred, shear, beat, etc., animal skins such ascowhide, rawhide, etc., or by combinations of these operations to yieldcollagen fibers which can be incorporated into the molded food toenhance its unit integrity. The amount of animal hides used as a sourceof collagen to be added to the molded product will depend upon manyfactors, such as for example, the type and amounts of fibers present inthe hide, the type of subdivision of the hide, the type of food in theproduct, whether swollen or unswollen collagen or hide binders or gelsare employed, etc. Collagen is a protein forming the chief constituentof connective tissue. In animal hide collagen constitutes the bulk ofthe fibrous protein, and for purposes of this invention is meant toinclude other fibrous protein such as elastin, reticulin, etc. Sincehides contain collagenous fiber bundles, cutting, chopping, shredding,shearing, etc. divide these bundles into smaller sections. When work isperformed on these cut segments, the smaller fibers are spread out overwider areas. Theoretically in the preparation of the product of thisinvention, the bundles of fibers are broken and then realigned so as toform fiber interlocks. To obtain maximum strength the cut fibersreinterlock in the final product so that a continuous fiber bond isformed to maintain the strength of the final product in the nature of arealigned fiber weave. In general, I place sufficient collagen fibers inthe product to impart the desired properties in the final product. Thus,as is clearly apparent, a suitable source of animal safely digestiblestructure-supporting fibers include fibers derived from animaltissue--for example from the skin, muscles, intestines, etc., ofanimals, for example, from tendons, animal hides such as cowhide,rawhide, etc. Since collagen is a digestible protein, it not onlymaintains the unit integrity of the product but also enhances its foodvalue. Thus, collagen is a protein supplement increasing the proteinvalue of the food.

With respect to cellulosic materials, cellulosic fibers are a suitablesource of animal safely indigestible structure-supporting fibers. Forexample, although cellulosic fibers are not digested by the pet, thepet's digestive system is capable of handling such fibers by passingthem through its system substantially unchanged and unchanged. In fact,cellulosic fibers provide increased roughage and bulk to the food so asto assist the pet in the digestion of food.

Further, with respect to collagen fibers as examples of said safelydigestible fibers, such include both collagen fibers which are obtainedfrom hides as well as collagen fibers which are prepared by dissolvingprotein and then precipitating the protein from solution and aligningthe molecules so as to obtain a fibrous material. Protein fibers arederived from soy protein, egg white, wheat gluten, etc. The fibrous formof these proteins are spun into continuous aligned filaments to yieldfood forms which simulate the fiber of natural beef. Examples thereofare disclosed in Belgian Pat. No. 634,140, U.S. Pat. No. 3,071,477 and3,197,310 and Cereal Chem 43 (2) 195 (1966). Animal protein such asanimal collagen may also be dissolved, precipitated and aligned to yieldreconstituted collagen.

One of the objects of this invention is to provide, as is clearlyapparent herefrom, simultaneously, compacted, shaped, molded andunitized, self-contained, unit-integral, chew-resistant animal foodsystem products, either unilayer or multilayer, as aforesaid and also asfurther hereinafter described, containing animal food andstructure-supporting fibers, as aforesaid and also as furtherhereinafter described, with said structure-supporting fibers present inthe products in amounts or amount sufficient to make my productschew-resistant, self-contained and unit-integral and to enable each ofthem to be and remain in compacted, shaped and molded form.

Other objects and features of my invention are readily apparent from theherein detailed description, as aforesaid and also as furtherhereinafter described, without any limitations thereon and onlyillustrative of those embodiments thereof herein described, aspreferred.

In general, the percent by weight of the animal safely digestiblestructure-supporting fibers, such as animal hide or other forms ofcollagens, or the percent by weight of the animal safely indigestiblestructure-supporting fibers, such as the cellulosic fibers, or thepercent by weight of the mixture of the two, in my unilayer food productembodiments comprises up to about 50% or more, such as from about0.5-40%, for example from about 1-30%, such as from about 1-10%, butpreferably from about 1-5%. The optimum amount will depend on variousfactors such as the thickness, length, etc., of the fibers, the desiredchew-life, etc.

In general, the percent by weight of the animal safely digestiblestructure-supporting fibers, such as animal hide or other forms ofcollagens, or the percent by weight of the animal safely indigestiblestructure-supporting fibers, such as the cellulosic fibers, or thepercent by weight of the mixture of the two, in my multilayer foodproduct embodiments comprises, in that particular layer where employed,depending on the desired hardness or chew-resistance of that particularlayer, up to about 50% or more, such as from about 0.5-40%, for examplefrom about 1-30%, such as from about 1-10%, but preferably from about1-5%. The optimum amount for the particular hardness will depend onvarious factors such as the thickness, length, etc., of the fibers, thedesired chew-resistance, etc.

In each of my unilayer and multilayer embodiments where the mixture ofthe two types of structure-supporting fibers is employed, the percent byweight of each type of fibers in the mixture of fibers can be within therange of 0-100% of weight of the mixture, for example, a mixture of 100%safely digestible fibers by weight of the mixture to 100% safelyindigestible fibers by weight of the mixture. For example, the mixtureof fibers may be any mixture within the range of 0-100% safelydigestible fibers to 100-0% safely indigestible fibers. Of course, withrespect to each of my multilayer embodiments, said mixture ranges applyto each particular layer thereof.

The following Example illustrates a method of preparing fibrouscollagens from hides.

EXAMPLE A

Essentially, the process employs cutters and shearing devices. The hideis cut into fiber bundles and the bundles sheared into fibers.

Hides are limed, fleshed, washed and adjusted to optimum pH. Pretreatedhides are conveyed to a cutter that exerts a scissor-like action. Fromthe cutter, the material is conveyed to a comminuating machine withopenings in the cutting heads ranging from 3/4 to 3/64 in. This machinecontrols the fiber length.

In addition to employing undigested collagen fibers, digested orpartially digested collagens or mixtures thereof can also beincorporated into the molded foods.

Cowhide can be digested by treating comminuted limed cowhide in diluteacid in the presence of a proteolytic enzyme such as for example:α-amylase, bromelin, ficin, pancreatin, papain, pepsin, steapin,trypsin, etc. so as to yield swollen collagen. The collagen can beincorporated into the food product and hardened therein. Both digestedand undigested fibers can be employed. In addition, completely digestedcowhide in the form of hide binder or gelatin, partially digestedcowhides such as swollen collagens, and undigested hides can beincorporated into the food. Hides may also be beaten or sheared toloosen the collagen and fiber structure and these fibers separated andincorporated into the food.

The following Examples are presented by way of illustration and not oflimitation.

EXAMPLE 1

Shredded cowhide (25% based on total weight of product) is blended intoa pulverized mixture of cereal and freeze dried meat suitable as a dogfood. Cowhide derived binder is also blended into the mixture. Theresultant mixture is molded into the shape of a bone to yield a producthaving sufficient strength on being consumed to sufficiently exercisethe dog's jaws and teeth.

EXAMPLE 2

Example 1 is repeated except that the product is molded into thefollowing shapes (1) a stick--(2) a dumbell--(3) a ball--(4) apaddle--(5) a ring--(6) a wishbone.

EXAMPLE 3

Example 1 is repeated except that cowhide is hydrolysed at a pH of about6.5 to a mass of slightly digested swollen collagen fibers with aproteolytic enzyme such as ficin and incorporated into pet foods toyield a bone shaped product on molding.

EXAMPLE 4

Example 3 is repeated except that both shredded cowhide (20%) andslightly digested swollen collagen fibers (5%) are incorporated into thepet food and then molded to yield the desired product.

EXAMPLE 5

Examples 1 through 4 are repeated except that an enzyme capable ofremoving plaque and/or tartar from the dog's teeth is incorporated intothe molded product. There products are such that there are incorporatedtherein neutral protease, alkaline protease or amylase mixture obtainedby fermenting with Bacillus subtilis NRRL-B-3411 as described in FrenchPat. No. 2,060,074 or any combination thereof.

EXAMPLE 6

Example 1 is repeated employing the following amounts of collagenobtained in Example A in the following amounts from 1 to 50%--i.e., 1%,2%, 3%, 4%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%.

EXAMPLE 7

Example 6 is repeated except that the products also contain slightlydigested swollen collagen fibers in a ratio of 1 part by weight ofswollen to 4 parts by weight of undigested collagen.

EXAMPLE 8

A pulverized mixture of cereal and freeze dried meat suitable as a dogfood is mixed with 5% of medical grade cellulose fibers. Cowhide derivedbinder is also blended into the mixture. The resultant mixture is moldedinto the shape of a bone to yield a product having sufficient strengthon being consumed to exercise the dog's jaw and teeth.

EXAMPLE 9

Example 8 is repeated with 5% of fibrous soya derived vegetable proteinto yield a molded bone capable of exercising the dog's teeth and jaws.

EXAMPLE 10

This example illustrates the use of baking as a means of preparing thecompacted product of this invention.

Collagen fibers were incorporated into cracker-type dough and baked toyield chew-resistant crackers. A range of concentrations of fibers wereincorporated into the dough, i.e., 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%,10%, etc., to yield a product which is more chew-resistant than crackersprepared without the fibers.

Baking was effected by both a batch-type as well as the continuous bakeextrusion process.

EXAMPLE 11

Shredded cowhide (5% based on total weight of product) is blended into apulverized mixture of cereal and freeze dried meat suitable as a dogfood. Cowhide-derived binder is also blended into the mixture. Theresultant mixture is molded into the shape of a rod to yield a producthaving sufficient strength to exercise the dog's jaws and teeth.

This hard rod is placed in a bone shape mold and surrounded with thesame pulverized mixture of cereal and freeze dried meat which containsneither shredded cowhide nor cowhide-derived binder to yield a soft andmore easily pulverizable outer layer. Thus the product has an inner hardcore and an outer soft layer, i.e., a hard/soft configuration asillustrated in FIG. 1.

EXAMPLE 12

Example 11 is repeated except that the inner core is soft (i.e., withoutshredded hide or cowhide-derived binder) and the outer layer is hard(i.e., with shredded hide and cowhide derived binder) to yield a softinner core and a hard outer layer (i.e., a soft/hard configuration asillustrated in FIG. 2).

EXAMPLE 13

Example 11 is repeated except that the outer layer contains onlycowhide-derived binder to yield a hard inner core and a soft, but lesscrumbly, outer layer (i.e., a hard/soft-hard configuration).

EXAMPLE 14

Example 12 is repeated except that the inner core containscowhide-derived binder to yield a soft, but less crumbly, inner core andan outer hard layer (i.e., a soft-hard/hard configuration).

EXAMPLE 15

Example 11 is repeated except that the outer layer contains 2% shreddedcowhide and a cowhide-derived binder to yield a hard inner core and aless hard outer layer (i.e., a hard/soft-hard configuration).

EXAMPLE 16

Example 12 is repeated except that the inner core has 2% shreddedcowhide and cowhide derived binder to yield a moderately hard inner coreand a hard outer layer (i.e., a soft-hard/hard configuration).

EXAMPLE 17

Shredded cowhide (71/2% based on total weight of product) is blendedinto a pulverized mixture of cereal and freeze dried meat suitable as adog food and cowhide derived binder is blended into the mixture and theresultant mixture molded into two rectangular blocks. The pulverized dogfood containing only cowhide derived binder is placed between these twoblocks and pressure exerted thereon to sandwich an inner softer layerbetween the two outer hard blocks to yield a unitary product (i.e., ahard/soft/hard configuration as illustrated in FIG. 3).

The principles of this invention are evident from the foregoingexamples. Likewise with the unilayer embodiments of my invention herein,as illustrated by the foregoing examples 1 through 10, employing theprinciple of varying layers of hardness in the multilayer embodiments ofmy invention herein, as illustrated by the foregoing examples 11 through17, employing various shapes such as a stick, dumbell, ball, paddle,ring, wishbone, etc., and employing as many layers as desired thecombinations herein are infinite such as 1, 2, 3, 4, 5, 6, 7, 8, 9, 10,or more layers.

In addition, both with respect to the unilayer embodiments of myinvention and to the multilayer embodiments of my invention, thecollagen employed in both the unilayer and the multilayer products ofthis invention can be digested collagen, vegetable protein, such asfibrous soya-derived vegetable protein, etc. Also, non-collagens such asanimal safely indigestible structure--supporting fibers, such ascellulose, etc., can be used in said products in place of the collagen.Also, as aforesaid, mixtures of the collagen, or collagens, and saidanimal safely indigestible structure-supporting animal fibers, thenon-collagens, such as cellulose, etc., can be employed in both myunilayer and multilayer embodiments, as aforesaid. My products also cancontain chemicals and enzymes for removing plaque and/or tartar such asBacillus Subtilis NRRL-B-3411 as described in French Patent 2,060,074,vitamins and other food supplements, etc.

With respect to both my unilayer and multilayer embodiments of thisinvention, certain non-limiting advantages of the unitary constructionof the instant invention are as follows:

(1) Less space is required in that the compaction of the componentsoccupies a smaller volume of space as compared to existing foods; thissmaller space requirement is very important in all phases ofmanufacturing, packaging, distribution and storage.

(2) The configuration of the unit can be designed to provide variousexposed facets and angles which may be brought into play to exercisevarious parts of the animal's mouth, teeth and gums as well as musclesin that to chew upon the unit, depending upon the angle of positioning,various surfaces of the unit and the animal come into contact providingan infinite number of combinations of contact.

(3) The extended chew-life imparted by the integrity of the unit permitsthe acting time of any additive or medicinal aid to be prolonged, thuspermitting more efficiency.

(4) The unitary construction permits an entire meal to be used as aconditioning tool under a variety of circumstances such as inretrieving, heeling, command control such as the discipline of noteating until given permission.

(5) Product identity can be embodied in the present invention in thatdifferent manufacturers may use different configurations todifferentiate their product from competitors.

(6) Component identity can be embodied in the shape or configurationimparted to denote contents and/or flavor. For example, a fish for thatflavor; a triangle or other distinctive shape for a particular flavor,etc.

(7) The ecological and conservation aspects of this system are importantin that the unitary construction permits the unit itself to beself-containerized eliminating in some instances the use and disposal ofa metallic container. The amount of wrapping that may be used isdiminished in that a smaller volume of space is used per unit of weightbecause of the compact nature of the invention.

While representative embodiments have been shown for the purposes ofillustrating the invention, it will be apparent to those skilled in theart that various changes and modifications may be made without departingfrom the spirit of the invention.

I claim:
 1. A simultaneously compacted, shaped, molded, and unitized,self-contained, unit-integral, chew-resistant animal food system productcontaining at least one chew-resistant layer with animal food as a partthereof and at least one lesser chew-resistant layer with animal food asa part thereof, said latter layer being less chew-resistant than saidformer layer, the chew-resistance of each of said layers being primarilycontrolled by the relative presence or absence of structure-supportingfibers, said structure-supporting fibers being a mixture of animalsafely digestible structure-supporting fibers and animal safelyindigestible structure-supporting fibers, said structure-supportingfibers being present in said animal food system product in said latterlayer and in said former second layer or in said latter layer or in saidformer layer in amounts or in an amount sufficient to make said animalfood system product chew-resistant, self-contained and unit-integral andto enable it to be and remain in its compacted shaped and molded form.2. The simultaneously compacted, shaped, molded, and unitized,self-contained, unit-integral, chew-resistant animal food system productof claim 1 wherein the animal safely digestible structure-supportingfibers are collagen.
 3. The simultaneously compacted, shaped, molded,and unitized, self-contained, unit-integral, chew-resistant animal foodsystem product of claim 2 wherein the collagen is derived from animalhide.
 4. The simultaneously compacted, shaped, molded, and unitized,self-contained, unit-integral, chew-resistant animal food system productof claim 1 which also contains supplemental additives.
 5. Thesimultaneously compacted, shaped, molded, and unitized, self-contained,unit-integral, chew-resistant animal food system product of claim 2which also contains supplemental additives.
 6. The simultaneouslycompacted, shaped, molded, and unitized, self-contained, unit-integral,chew-resistant animal food system product of claim 1 wherein the animalsafely indigestible structure-supporting fibers are cellulosic.
 7. Thesimultaneously compacted, shaped, molded, and unitized, self-contained,unit-integral, chew-resistant animal food system product of claim 6which also contains supplemental additives.
 8. The simultaneouslycompacted, shaped, molded, and unitized, self-contained, unit-integral,chew-resistant animal food system product of claim 1 wherein the animalsafely digestible structure-supporting fibers are collagen and theanimal safely indigestible structure-supporting fibers are cellulosic.9. The simultaneously compacted, shaped, molded, and unitized,self-contained, unit-integral, chew-resistant animal food system productof claim 8 which also contains supplemental additives.